if your car is like my C5 its an alloy rear axle. what i found out after weeks and weeks of investigation , the brake caliper is steel and reacts with the alloy axle what you have to do is take off the caliper (no mean feat i can tell you, use quality tools) the clean off the corrosion you will find there and apply some preventative to corrosion) I used a good dolop of coppaslip grease. rebolt on the caliper and fit new pads hey presto squeeling removed.
Mark D, April 2009
